Just go to the beach, you won't get "white" white, but you can get sorta-close to white. If memory serves there's a beach near San Gregorio along the coast that has a salt & pepper colored sand (more pepper than salt), Monterey had white beaches. Bottom line is you're not going to get southdown or any type of "white" sand (atleast that you want to use for a kids play box) for home depot "Play Sand" prices. You could get sand blasting sand but as fine as that stuff is I would not recommend it for a kids play area.